First, System 7 is emulated using Mini vMac from the namedfork.net source you can find in the Cydia > Repositories section. Secondly, if you go to add the shockdevteam.com source (manually), you can get Bochs for iPhone (the one for iP4 works on iPt4) and Windows 95 for Bochs. Voilą! You have Win 95 and System 7 (you have to find your own System 7 and vMac ROM)! They're both super useless though, just that Win 95 is cool to show off to people.

If u can't find iDos on cydia, use hackulouse repo's Installouse... Who said it's just for pirating ... Same thing when flash light tethering got pulled, still on instalouse

I think the reason people can't find DOSpad in Cydia even after adding litchie.net/cydia is because no one wants to see the mostly horrible games on Cydia and they all have the 'Games' section turned off.

<<Now that Dos can be emulated on an iOS device can Macintosh System 7 be far behind>>
You can install a dos version of a Mac emulator and do this, possibly even more recent systems (probably not OS X though)